Retrieve a GIF's palette entries using Python Imaging Library (PIL)

[Stuart]

I am using the Python Imaging Library (PIL) to process GIF images. I
need to be able to retrieve the RGB values for each color palette entry.

I see that the 'Image' class has a 'palette' attribute which returns an
object of type 'ImagePalette'. However, the documentation is a bit
lacking regarding how to maniuplate the ImagePalette class to retrieve
the palette entries' RGB values. Can anyone point me to a short example?

Thanks!

[and-google]

Stuart wrote:

I see that the 'Image' class has a 'palette' attribute which returns an
object of type 'ImagePalette'. However, the documentation is a bit
lacking regarding how to maniuplate the ImagePalette class to retrieve
the palette entries' RGB values.

ImagePalette.getdata() should do it.

There seems to be some kind of bug, however, where Images lose their
ImagePalettes after being convert()ed to paletted images (eg. using
Image.ADAPTIVE). For this reason I personally use the getpalette()
method from the wrapped image object, which seems to contain the proper
raw palette data. For example to get a list of [r,g,b] colour lists:

def chunk(seq, size):
return [seq[i:i+size] for i in range(0, len(seq), size)]

palette= image.im.getpalette()
colours= [map(ord, bytes) for bytes in chunk(palette, 3)]

--
And Clover
mailto:an*@doxdesk.com
http://www.doxdesk.com/